There are tons of comets in our solar system. They usually do not get close to the earth.
The Sun is at the center and is very bright.
A comet is made of ice and rock and has typical size of 10 km in diameter. The largest is 10199 Chariklo at 258 km.
Nasa reports there are 3743 known comets. There is likely billions of them that we do not know about.
Images from NASA:
The next appearance will be in 2061.
The comet’s perihelion (closest approach to the Sun) is only 0.6 AU, and it travels as far from the Sun as beyond the orbit of Neptune. As a result, Halley is not visible from Earth (with naked eyes) when it passes through perihelion.
Q: What’s a comet, anyway? A: A comet is like the drama queen of the solar system, always making a flashy entrance! It’s a cosmic snowball made up of ice, rock, and dust that orbits the Sun. When it gets close to the Sun, the ice starts to vaporize, creating a glowing coma and often a spectacular tail.
Q: How is a comet different from an asteroid or a meteor? A: Think of them as distant relatives with different lifestyles. Asteroids are rocky and hang out mostly in the asteroid belt between Mars and Jupiter. Meteors are tiny specks of dust or debris that burn up in our atmosphere – you might know them as shooting stars. Comets, on the other hand, are icy and spend most of their time in the outer solar system.
Q: What’s a comet’s tail made of? A: A comet’s tail is like its personal banner, waving in the solar wind. It’s made up of gas and dust that has been heated by the Sun and pushed away by the solar wind. The cool part? It always points away from the Sun, no matter which direction the comet is moving!
Q: Can I see a comet from Earth? A: Sure, if you’re patient and a bit lucky! Comets are like the celebrities of the night sky – they don’t come out often, but when they do, they put on quite a show. Some comets are visible to the naked eye, but others require a telescope. And remember, no two comets are alike, so each appearance is unique!
Q: Are comets a danger to Earth? A: While comets have been known to put on a scary movie-worthy performance as they streak across the sky, they’re generally not a threat to Earth. Our planet’s atmosphere is like a bouncer at a nightclub – it does a great job of protecting us from incoming objects. If a comet did come too close, it would likely burn up in our atmosphere.
Q: What have we learned from studying comets? A: Comets are like the time capsules of the solar system. They’re made from the same stuff that was present when the Sun and the planets formed, so by studying them, scientists can learn more about our cosmic roots. Missions like Rosetta, which landed a probe on a comet, have given us valuable insights into these celestial snowballs.
Comet 103P/Hartley (Hartley 2)
The nucleus of Hartley 2 is estimated to be 3.4 kilometers long, 2.1 kilometers wide and it rotates every 12 hours at the average distance of 2.2 AU from the sun. The coma around its nucleus extends about 20,000 km into space though this could be closer depending on the activity level of the comet’s nucleus. Comet Hartley 2 is moving toward the sun, where it will reach perihelion on November 27, 2010.
Comet Siding Spring Seen Next to Mars
Oort cloud comet C/2014 Q2, aka Lovejoy
Six comet-like tails radiating from a body in the asteroid belt, designated P/2013 P5
Comet Siding Spring
Hubble View of ISON
Composite photo, images of Jupiter and Comet P/Shoemaker-Levy 9
They are fast moving. Example speeds:
Borisov 175,000 km per hour
Neowise 230,000 km an hour
Leonard 254,400 km per hour
The time it takes to travel one orbit is the period, here are examples from NASA data:
Halley 76.1 yrs.
Encke 3.30 yrs.
d’Arrest 6.51 yrs.
Tempel 1 5.51 yrs.
Borrelly 6.86 yrs.
Giacobini-Zinner 6.52 yrs.
Grigg-Skjellerup 5.09 yrs.
Crommelin 27.89 yrs.
Honda-Mrkos-Pajdusakova 5.29 yrs.
Wirtanen 5.46 yrs.
Tempel-Tuttle 32.92 yrs.
Churyumov-Gerasimenko 6.57 yrs.
Schwassmann-Wachmann 3 5.36 yrs.
Kohoutek 6.24 yrs.
West-Kohoutek-Ikemura 6.46 yrs.
Wild 2 6.39 yrs
Chiron 50.7 yrs.
Wilson-Harrington 4.29 yrs.
Hale-Bopp 4000. yrs.
Hyakutake 40000. yrs.
Pictures of comets:
More cool pictures of comets: